1. Technical Field
The present invention relates to decorative components and, more particularly, to decorative automotive components having a molded elastomeric outer layer. The invention also relates to methods of making such decorative components.
2. Discussion of the State of the Art
A recent trend in the automobile industry has been the development of various non-fabric automotive trim components. Among the known systems for producing decorative components are polyvinyl chloride (PVC) vacuum and rotocast systems, thermoplastic polyolefin (TPO) vacuum formed systems, thermoplastic polyurethane (TPU) rotocast and sprayed aliphatic urethane systems generally. However, each of the foregoing systems present certain perceived drawbacks. For example, the known PVC vacuum form and rotocast systems are initially considered undesirable in that PVC is considered to be difficult to recycle and environmentally unfriendly, i.e., subject to releasing dioxins and other chlorinated by-products upon decomposition. Further, an unnecessarily thick skin is required to minimize the effects of plasticizer loss over time. PVC skins, particularly those which are vacuum formed, are often stiff and have a poor feel.
TPO vacuum formed systems are also often stiff and have a poor feel. Further, the grain definition of the resultant components are considered to be poor in quality. Additionally, TPO skins must often be coated to improve their resistance to scratch and mar resulting in increased costs and labor.
Accordingly, U.S. Pat. No. 5,116,577 to Dabaes et al. attempted to address many of the aforementioned drawbacks seen in PVC and TPO systems, as well as certain integral skin applications by developing a method for manufacturing mold components having a relatively low density, i.e., less than 700 g/dm3. The method is said to involve applying a layer of light stable polyurethane elastomer having a predetermined color onto a mold surface by spraying and thereafter injecting in the space of the mold cavity while the elastomer is still tacky a synthetic foam composition. Upon curing of both the elastomer layer and the synthetic foam, the resultant object is removed from the mold.
While the Dabaes patent arguably provides for an advancement in the art, certain perceived drawbacks are seen regarding its teachings. For example, the required use of a light stable aliphatic polyurethane elastomers for the external layer of the object is believed to greatly increase the cost of the resulting component. Further, the resulting elastomer often requires additional treatment to achieve adhesion to a urethane foam. Other perceived drawbacks include poor color matching with other components, poor fogging resistance, and poor feel due to the relatively thick skins that are typically achieved in practice.